Activation of Yeast Mitochondrial Translation: Who Is in Charge?

Abstract

Mitochondrial genome has undergone significant reduction in a course of evolution; however, it still contains a set of protein-encoding genes and requires translational machinery for their expression. Mitochondrial translation is of the prokaryotic type with several remarkable differences. This review is dedicated to one of the most puzzling features of mitochondrial protein synthesis, namely, the system of translational activators, i.e., proteins that specifically regulate translation of individual mitochondrial mRNAs and couple protein biosynthesis with the assembly of mitochondrial respiratory chain complexes. The review does not claim to be a comprehensive analysis of all published data; it is rather focused on the idea of the "core component" of the translational activator system.

Absolute yeast mitochondrial proteome quantification reveals trade-off between biosynthesis and energy generation during diauxic shift

“…S5 E and G). This pattern can be justified by the fact that the core subunits of the respiratory-chain complexes are synthesized locally by mitochondrial ribosomes (48). Otherwise, we observed that some functional protein groups (Heme biosynthesis and proteins involved in the mitochondrial genome maintenance; SI Appendix, Fig.…”

Msc6p is required for mitochondrial translation initiation in the absence of formylated Met‐tRNAfMet

“…Therefore, accordingly to the data presented here, we hypothesized that in the absence of formylated methionyl‐tRNA, Msc6p is required for proper expression of mitochondrially encoded products. Different studies on mitochondrial translation have unveiled a multitude of factors involved in this process , particularly Cox1p whose translation involves a number of regulatory steps from mRNA processing to the newly synthesized stabilization .…”

Modular biogenesis of mitochondrial respiratory complexes

“…The dependence on two separated genomes for proper assembly of the respiratory complexes required the development of a balanced output of gene products destined to be subunits of the same enzyme. Mitochondria translational activators are the primary candidates to exert such control (Costanzo and Fox, 1990) in three proposed ways: through the recognition of a specific 5' UTR end, which is the case of Cbp1p, Cbs1p and Cbs2p; by a direct interaction with the mitoribosome (Cbs1p, Cbs2p, Cbp3p and Cbp6p); and finally interacting with the nascent polypeptide chain at the mitoribosome tunnel exit (Cbp3p and Cbp6p) (Derbikova et al, 2018;Ndi et al, 2018).…”